Method of making conveyer and elevator screws



Aug. 11, 1931. F, R. MCFARLAND METHOD OF MAKING CONVEYER AND ELEVATOR SCREWS Fild June a, 1928 2 Sheets-Shan 1 NW 'ENTOR. WM

M Q/wm A TTORNL' 3 Aug. 11, 1931. F. R. M FARLAND METHOD OF MAKING CONVEYER AND ELEVATOR SCREWS Filed June 8, 1928 2 Sheets-Sheet 2 INVENTOR. 5104, A. MW

A TTORNE Y.

Patented Aug. 11, 1931 TES PATENT OFFICE FRANK R. MCFARLAND, OF CUMBERLAND,

METHOD OF MAKINGiCONVEYER AND ELEVATOR SCREWS Application filed .Tune 8,

7 My invention relates to elevator and conveyer screwsfor all types of stokers, both for steam locomotives and other types of service, such as stationary plants, coal mines,

p pulp paper mills, etc.

My invention consists of an improvedmethod of making and reclaiming such elevator and conveyer screws.

In screws of this class, especially those lofhandling coal and other 'gritty substances, it has been found that the blades or flights of the screw wear, or are ground off both in height and in thickness, and the substance conveyed rolls back between the edges of the 15. flights and the casing or trough in which they costs approximately $75.00and a conve er, screw $100.00, and that on a railroad having 875 stoker fired locomotives the yearly average consumption of these screws is 85 elevator screws and 163 conveyer screws, at a cost of $21,597.00, whereas, by the use of my method these worn screws can be reclaimed at an average of $6.67 apiece, from which it will be seen that a very material saving results from the practice of my invention, as has been shown by actual commercial use of my invention.

In the drawings:

Figure 1 is a side elevation of a screw as it appears after the first step of my method has been performed.

Figure 2 is a detail view of portions of the flight ready for application-to Figure 1.

Figure 3 is a side elevation of a screw showing the flights applied to Figure 1.

Figure 4 is a detail sectional view of the flight of a screw according to the old practicecast integral with the stem.

Figure 5 is a similar view showing in full 1928. Serial No. 283,777.

lines the shape to which the flight in .Figure 4 is worn.

Figure 6 is a detail view illustratin the first step of my method showing the flig t in Fi ure 5 cut 011' to. the front shown.

igure 7 is a detail view showing the assembly of the new flight to Figure 6.

'Fi ure 8 is a view similar to Figure 7 showing t e next step in my method, which is the electric welding of the new flight.

Figure 9 is a view similar to Figure 8 showing thefinished product. 1

Figure-1O is an end elevation of the completed screw.

Figure 11 is a perspective view of my new flight in the process of formation.

The reference numeral 12 designates the stem of a conveyer screw to which the flight 13, according to the old process is cast integrally. Experience has shown that the integral flights gradually wear away as shown in full lines in Figure 5 to a tapered body (the dotted lines in this fi re indicating the original thickness of the ight) When this condition exists theflight is very susceptible to bending or fracture, therefore, according to the old practicea screw in the condition shown in Figure 5 is scrapped and becomes a total loss, the cost of which is stated above. It is necessar for a railroad to carry, at all times, a stool; plrgmptly substitute the new screw for the o 1 According to my invention these screws may be reclaimed at a very nominal cost, which results in a material annual saving as herein related.

According to my invention, when a screw is worn, as shown in Figure 5, this worn screw is put in a machine and the worn flight is cut off to the point 14, Figure 6, or it may be removed by acetylene torch. The next step is to place a metal strip (constituting the new flight 15) in a machine 16 and coil it to the required pitch of the flight as shown in Figure 11. It will be seen that the machine 16 is provided with grooves into which the metal strip 15 is introduced and that these grooves are pitched to bend the strip 15 to the desired pitch and coil, the flight being continuous in of new screws in order to one piece for the screwl The inner ed e of the strip 15 is provided with -a double evel point or edge 18.

After the flight 15 is thus formed,'it is assembled on the stem 12, Figures 1' and 7,

with the bevel edge 18 resting on the surface 14. The next stepis to apply the electric welding metal 19 in the welding-recesses and securing the flight to the stem 12, after which the surplus metal of the weld is removed as ShOWiliin Figure 9,. thereby completing the screw as shown in Figure 3.

New screws may be originally constructed accordin to m invention as will be obvious 15 to those s 'lled 1n the art, thereby eliminating large expensive steel castings that are difli cult to cast, and at the same time produce a better screw for the purpose, because the stem may be made from simple molds and of cast or drawn malleable metal strips, with the flights of, for instance, open hearth'steel,

continuous flight.

What I claim is: 1. The method of making elevator and conveyer screws which consists in casting the stemwith stub flights, then-welding a full flight of malleable metal to said stubflights.

2. The method of reclaimingelevaton-and conveyer screws-which consists of cutting the worn flights down to stubs, then assembling a full flight of malleable metal on said stubs, and then welding said full flights to saidstubs. Y

I 3.- The method of reclaiming elevator and conveyer screws, which consists in cutting the worn flights down to stubs, coiling a metal strip to form a flight of the re ui-red pitch,

fitting the-flight strip about t e conveyer stem and upon said stubs, and then weld ng the strip to the stubs.

4. The method of reclaiming elevator and vconveyer screws, which consists in cutting the worn flights down to stubs, coiling a metalstrip having a V-shaped edge so as to form a flight strip of the required pitch, assemblin said flight rip about the conve or stem wit its V-shape edge bearing on t e stubs so as.

to form recesses at each side of the strip and between the same and each stub, and then depositin welding metal in said recesses so as to wel the strip tothe stubs. 1

5. The method of reclaiming elevator and conveyer screws, which consists in cutting the worn flights down to stubs, coiling a metal strip to form a flight of the re uired'pitch,

fitting the flight strip about t e conveyer stem and upon said stubs, then welding the strip to the stubs, and then shapin the deposlted metal to the desi of the flig ts.

6. The method of rec aiming-elevator and its V-shaped e ge bearing on the stubs so as to form recesses at each side of the strip and between the same and the stubs, then depositin welding metal in" said recesses so as to 'we d the stri tothe stub, and then shaping the deposit fli hts.

- The method of making elevator and conveyer screws, which consists in casting a conveyer stem-with stub flights, coiling a'metal metal to the design' of the stripto provide a flight of the required'pitch- Q and formed to fit the stub flights, disposing the flight strip upon the stub flights on the conveyer stem, and then welding the strip to the stub flights.

a 8. The method of making elevator and conveyer screws, which consists in casting a conveyer stem with stub fli hts, coiling a metal strip having a V-shape edge so as to form a flight strip of the required pitch, assemblin said flight strip about the conve er stem witfl its'V-shaped edge bearin on t e stubs so as to form recesses. at each side of the strip and between the same and-each stub, and then (161 positing welding metal in said recesses so as to weld the strip tothe stubs.

9. The method of niaking elevator and conveyerscrews, which consists in casting a conveyer stem with stub fli hts, coiling a metal strip to form a fli ht o the required pitch,

assembling the flig t strip upon the conveyer stem, then welding the stri to the stubs, and

then shafim the deposite metal to the design of t e ight.

10. The method of making elevator and conveyer screws, which consists in casting a conveyer stem with stub fli hts, coiling a metalstrip having a V-shape ed e so as to form a flight stri of the require pitch, assembling said flig t strip about the conveyer stemwith its V-shaped edge bearin on the stubs so as 'to form recesses at each si e of the strip and between the same and the stubs, then depositin welding metal in said recesses so as to wel the strip to the stub, and then sha ing the deposited metal to the design of t e flight.

i 11. The method of reclaiming elevator and conveyer screws, which consists in cutting off-the worn flights down to stub flights, securing one end of a malleable metal strip to a helically grooved rotatin mandrel winding.

said strip in the groove 0 the mandrel while simultaneously guiding and bendin said strip into shape, so as to produce a heflically formed full flight of the same itch and internal diameter conforming to e external diameter of the stub flight of the stem, fitting said full flight on the stub flight of the stem,

and welding the same thereto.

12. The method of producing an elevator and conveyer screw, which consists in providing a cast metal stem having helically arranged stub flights cast integrally therewith, securin at one end to a rotating helically groove mandrel a malleable metal strip, winding said strip in the groove of the mandrel while guidin said strip and bendin it to conform to t e shape of the man rel groove, so as to form a full flight strip corresponding in .pitch to and of an internal diameter conforming to the external pitch of the stub flights, removin said helical strip from the mandrel and isposing the same about the stub flights of the stem, and then weldin said stri to the stub flights.

13. he metho of reclaiming elevator and conveyer screws, which consists in producing an electric are, burning away the worn flights of the conveyer down to stub flights b means of such are, orming a malleable meta helical full flight of the same pitch as the stub flights and of an internal diameter correspondin to the external diameter of the stub fli its, fitting said strip upon the stem and .aiout said stub flights, and welding said strip to said stub flights.

In testimon whereof I aflix my signature.

RANK R. McFARLAND. 

